65110968c5
For stable branches, we currently only check out the correct mutter branch for merge requests. For the regular pipeline, our code to determine the current shell branch fails because CI runs on a temporary "pipeline/12345" branch that doesn't exist for mutter. Switching to the correct gitlab environment variable fixes that. https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/811 (cherry picked from commit fd5989e99a3bbaa978c0dd4cd55d1fc677c175da)